hey can someone check the morgan theorem for me ! I will reply with my answers soon as i compare answers 1. A(Complement) x B x C(complement) and its all complemented ... I hope its easy to understand hehehe Thanks

What does the x mean? Doesn't DeMorgan's theorem just involve complementing all the operands and reversing the ANDs and ORs? Also, as you're the original poster and it's a learning exercise, if you want any answers you should post your own first along with how you got them...Then we can guide you in the right direction without giving answers. Good luck, -SN

Typically complemented variables are written as A' or on paper as A bar (A with a horizontal bar over it). (A' and B and C')' ? I don't get what your question is - use demorans theorem to find an equivalent expression? (A'BC')' == (A')' + B' + (C')' == A+B'+C If I understand correctly your question then (A or B' or C) it the answer. An enumerative proof with a truth table: R = (A'BC')' S = A+B'+C A B C| R | S ------------ 0 0 0| 1 | 1 0 0 1| 1 | 1 0 1 0| 0 | 0 0 1 1| 1 | 1 1 0 0| 1 | 1 1 0 1| 1 | 1 1 1 0| 1 | 1 1 1 1| 1 | 1

I think the xs are supposed to represent and operations. Typically ands are written as hats: ^ A^B == A and B == AB and ors are typically written as AvB == A or B == A+B You can think of A and B as a sort of multiplication. But it is still usually not written with a * or x symbol (A*B or AxB).

De Morgan's Laws (not Theorem). There is a related De Morgan duality principle too. Notation varies depending on context and taste but the \vee and \wedge pair are usually used in logic, not boolean algebra or set theory. Set theory notation: usually cup, cap and ' or superscript c for complement. Propositional calc: usually v ([la]tex \vee), & or ^ ([la]tex \wedge) and ~ for complement. Boolean algebra (presumably the relevant context here): usually +, . ([la]tex \cdot) or sometimes x ([la]tex \times) and primes or a bar for complement.

Thanks geohoffman49431,Wolfbone, SN. It's fully clear to me now.